When Toyota first started creating their own US factories, they took the steps of shipping floor employees in the US to japan a few at a time and working for weeks of training each class. When other auto companies tried to replicate Toyota processes in their own factories, it didn't help yield in the factories in many cases because often the input supplies needed so much rework. And then they had problems changing suppliers configurations because those relationships were contentious, and not of the nature of Toyota to it's suppliers. When you're trying to stand the whole system up at once, it's not just a matter of "don't write bugs" in one part of the final assembly.
When Boeing reworked it's production design process for the 787, they had years of production problems to re-iron out, despite having years of great process experience previously.
The question that follows on: What internal process has prevented that experience from being bought? Instead Tesla seems to have opted to gain that experience from scratch at great cost to investors (and consumers).